Hi. I just bought a game called Element Z on steam. So far I am enjoying it but I am stuck.

After the train moves the first time and then breaks down there is a shop that you have to break into. I have gotten into the shop and accessed the roof done what I could in the roof and re-entered the shop. Now I can't leave the shop or re-enter the roof. It tells me there is still something value to find. I assume it's either to do with the security camera or drink machine. The items in my inventory are: key, walkiez, postcard, book, a piece of paper(if I try to combine with walkiez it says something is missing), makeshift crowbar, ballet ticket, old watch.

I have tried all the combinations I can think of. Please help

The only help I could find for this game online at this point is this YouTube video which is part one of a walkthrough. I don't know if your question would be answered by watching this or not, but you could check it out and see.

Otherwise, I hope that someone else playing the game will be able to help you out.